Method for refining ultraviolet absorbent, ultraviolet absorbent and cosmetic material

ABSTRACT

The process for purifying an ultraviolet absorber of the present invention is characterized by including an adsorbent treatment step of bringing the ultraviolet absorber into contact with an absorbent. According to the process, an ultraviolet absorber having a reduced odor, an improved hue and less skin irritation can be obtained.

TECHNICAL FIELD

The present invention relates to a process for purifying ultravioletabsorbers, in particular, to a process for purifying ultravioletabsorbers in which aldehydes, as causative substances of odor, containedin the ultraviolet absorbers are specifically removed. The presentinvention also relates to an ultraviolet absorber having a reduced odorand an improved hue and cosmetics that contain a purified ultravioletabsorber.

BACKGROUND ART

To prevent harmful effects on the skin by ultraviolet rays, manycosmetics having ultraviolet preventing effect have been developed.Traditionally, such cosmetics contain an ultraviolet absorber such as aderivative of cinnamic acid, benzophenone, para-aminobenzoic acid orsalicylic acid. Of the above described derivatives, derivatives ofcinnamic acid or salicylic acid have been often used, from the viewpointof safety, compatibility with cosmetic base materials and ultravioletabsorptivity. As the cinnamic acid or salicylic acid derivatives, therecan be mentioned; ester compounds such as ethyl p-methoxycinnamate;isopropyl p-methoxycinnamate; 2-ethylhexyl p-methoxycinnamate; glycerylmono-2-ethylhexanoate di-p-methoxycinnamate; octyl salicylate; phenylsalicylate; homomenthyl salicylate; dipropyleneglycol salicylate;ethyleneglycol salicylate; myristyl salicylate; and methyl salicylate.

Generally, the above described ultraviolet absorbers are poor inlong-term stability, and thus they can be oxidized and deteriorate withtime and sometimes give an odor or color. Thus, the cosmetics containsuch ultraviolet absorbers together with a stabilizer, such asbutylhydroxy toluene (BHT) or tocopherol as an antioxidant. However,ultraviolet absorbers composed of a compound having an aromaticstructure often contain substances having a characteristic odor or skinirritation or a coloring material from the outset. Even if anantioxidant is added to such ultraviolet absorbers, the substances orcoloring material remains in the ultraviolet absorbers; as a result,when using cosmetics or the like that contain an sufficient amount ofultraviolet absorber to give ultraviolet preventing effect, one cansometimes feel a characteristic odor or skin irritation or find color inthem. Thus, an ultraviolet absorber having a reduced odor, color andskin irritation have been demanded.

As one example of processes for reducing an odor of ultravioletabsorbers, Japanese Patent Application Laid-Open No. 1995-89835discloses a process in which odor substances contained in an ultravioletabsorber are removed by physical adsorption, specifically by bringingthe ultraviolet absorber having been diluted with a solvent, such ashexane, into contact with an adsorbent such as silica gel. By theprocess disclosed in the above patent application, however, butylhydroxytoluene or tocopherol, which has been added as an antioxidant to theultraviolet absorber, is also adsorbed together with the odor substancesby the adsorbent; thus, the process possesses a problem of being unableto suppress the deterioration with time of the ultraviolet absorption orthe formulated cosmetics.

Further, the process disclosed in the above described patent applicationrequires a large amount of solvent and adsorbent, which is problematicin terms of safety or environments of the operation as well as cost,when it is used in industrial production; thus, the process is notpractical.

Accordingly, the object of the present invention is to provide a processfor purifying an ultraviolet absorber, that is excellent in industrialproductivity, an ultraviolet absorber obtained by the above purifyingprocess which has a reduced odor, an improved hue and less skinirritation, and cosmetics using the ultraviolet absorber.

DISCLOSURE OF THE INVENTION

The inventors of the present invention carried out an in-depth study toaccomplish the object. As a result, they have found that an ultravioletabsorber having a reduced odor and an improved hue can be obtained bybringing an ultraviolet absorber into contact with an adsorbent. Andthey have finally accomplished the present invention.

The present invention has been accomplished based on the above finding.According to the present invention, there is provided a process forpurifying an ultraviolet absorber, characterized by including anadsorbent treatment step of bringing an ultraviolet absorber intocontact with an adsorbent.

According to the above described process for producing an ultravioletabsorber, aldehydes contained in an ultraviolet absorber can beselectively removed, and thus an ultraviolet absorber having a reducedodor and an improved hue can be obtained.

The above described adsorbent is preferably an amino-modified silica gelobtained by allowing silica gel to react with a silane coupling agenthaving a primary amine group to modify the surface of the silica gel.

The above described adsorbent is preferably such that the amount of theprimary amine group supported on the adsorbent is 0.4 to 1.5 μmole permg of silica gel.

The above described ultraviolet absorber preferably contains at leastone kind of ester compound that is composed of an aromatic fatty acidand a monohydric- or polyhydric-alcohol.

The above described ultraviolet absorber preferably contains at leastone kind of ester compound that is composed of methoxycinnamic acid anda monohydric- or polyhydric-alcohol.

The above described process for purifying an ultraviolet absorberpreferably includes a deodorizing treatment step after the abovedescribed adsorbent treatment step.

The present invention also provides an ultraviolet absorber having beenpurified by the above described process for purifying an ultravioletabsorber.

The present invention also provides a cosmetic that contains the abovedescribed ultraviolet absorber.

BEST MODE FOR CARRYING OUT THE INVENTION

A process for purifying ultraviolet absorbers according to the presentinvention is described in detail below.

The term “ultraviolet absorber” as used herein means an ultravioletabsorber containing, as a main ingredient, at least one kind of estercompound that is composed of an aromatic fatty acid and a monohydric- orpolyhydric-alcohol. As such ester compound, there can be mentioned;ethyl p-methoxycinnamate; isopropyl p-methoxycinnamate; 2-ethylhexylp-methoxycinnamate; glyceryl mono-2-ethylhexanoatedi-p-methoxycinnamate; octyl salicylate; phenyl salicylate; homomenthylsalicylate; dipropyleneglycol salicylate; ethyleneglycol salicylate;myristyl salicylate; methyl salicylate; and the mixture thereof withother general-purpose ester compounds. An ultraviolet absorbercontaining, as a main ingredient, at least one kind of ester compoundthat is composed of methoxycinnamic acid and a monohydric- orpolyhydric-alcohol is particularly preferable as the ultravioletabsorbers which the process for purifying an ultraviolet absorber of thepresent invention is intended for. Such ultraviolet absorber ispreferably used in cosmetics, from the viewpoint of safety andultraviolet absorptivity.

The process for purifying an ultraviolet absorber according to thepresent invention includes an adsorbent treatment step of bringing anultraviolet absorber into contact with an adsorbent.

The adsorbent treatment may be carried out by first dissolving anultraviolet absorber in a solvent and then bringing the ultravioletabsorber dissolved in the solvent into contact with an adsorbent or bybringing an ultraviolet absorber directly into contact with an adsorbentwhile avoiding the process of dissolving the ultraviolet absorber in asolvent. When the process employs a solvent, as the solvents applicable,there can be mentioned; n-hexane, n-heptane, petroleum ether, ethylacetate, isobutyl acetate, methyl ethyl ketone, ethyl alcohol, isopropylalcohol, and the mixtures thereof.

In the present invention, however, it is preferable not to use asolvent, from the viewpoint of industrial productivity (productioncost), influence on the environment, reduction of the number of steps,and safety during the production. In other words, it is preferable tobring an ultraviolet absorber directly into contact with an adsorbent.

The adsorbent used in the present invention is for adsorbing odorsubstances contained in an ultraviolet absorber. As such adsorbents,there can be mentioned; synthetic adsorbents containing an oxide (orhydroxide) of Mg, Al or Si, as a constituent. Concrete examples include:silica gel; activated clay; activated alumina/magnesia anhydride; andactive alumina/magnesia hydrate. Either one of these adsorbents alone ortwo or more in a properly mixed form can be used.

The particle diameter of the adsorbent used is preferably 0.1 to 3 mm,more preferably 0.1 to 0.5mm. If the particle diameter is within theabove described range, a sufficient adsorbent treatment speed can beobtained, and moreover, the adsorbent can be easily separated from theultraviolet absorber after the adsorbent treatment.

As the adsorbents applicable to the process for purifying ultravioletabsorbers of the present invention, there can be mentioned; silica gelwith a primary amine group supported thereon. Such silica gel ispreferably used in the process for purifying ultraviolet absorbers ofthe present invention.

A primary amine group reacts specifically with aldehydes to form orangeto red Schiff's salts, as shown in the reaction formula below. Since aprimary amine group and an aldehyde chemically bond with each other, thealdehyde never leaves from the adsorbent. The adsorbent reactingspecifically with aldehydes can selectively remove aldehydes containedin ultraviolet absorbers, even if the concentration of the aldehydes isvery low.Silica-NH₂+R—CHO→Silica-N=CHR+H₂O

As the adsorbent used in the process for purifying ultraviolet absorbersof the present invention, amino-modified silica gel is preferable whichis obtained by allowing silica gel to react with a silane coupling agenthaving a primary amine group to modify the surface of the silica gel.Such amino-modified silica gel has the advantage that aldehydes asdescribed above do not leave from it, because the primary amine group isnot liberated from the silica gel easily due to the chemical bond of thesilanol group to the surface of the silica gel, and therefore itchemically bonds with aldehydes.

Processes for preparing amino-modified silica gel include: for example,not limited to, a process which includes the steps of: making silica gelinto a slurry with an appropriate solvent; adding a silane couplingagent having a primary amine group; allowing the silica gel and thesilane coupling agent to react with each other at ordinary temperatureto 120° C. for 2 to 24 hours; if necessary, cleaning and solid-liquidseparating the mixture; and drying the same.

The silica gel used in the process for purifying ultraviolet absorbersof the present invention preferably has pore diameter of 5 nm to 40 nmand more preferably 6 to 15 nm, considering its reactivity with a silanecoupling agent and its steric effect with aldehydes. Further, the silicagel used in the process for purifying ultraviolet absorbers of thepresent invention preferably reacts with a silane coupling agent on alarge specific surface area. Specifically, the specific surface area ispreferably 100 m²/g to 800 m²/g.

As the silane coupling agents having a primary amine groups, there canbe mentioned;

-   4-aminobutyltriethoxysilane,-   2-aminoethylaminomethylbenzyloxydimethylsilane,-   (aminoethylaminomethyl)phenethyltrimethoxysilan-   e, N-(2-aminoethyl)-aminopropyltrimethoxysilane,-   N-(6-aminohexyl)-aminopropyltrimethoxysilane,-   3-(m-aminophenoxy)propyltrimethoxysilane,-   m-aminophenyltrimethoxysilane,-   p-aminophenyltrimethoxysilane,-   3-aminopropyldiisopropylethoxysilane,-   3-aminopropyldimethylethoxysilane,-   3-aminopropylmethyldiethoxysilane,-   aminopropylsilanetriol,-   3-aminopropyltriethoxysilane,-   3-aminopropyltrimethoxysilane,-   3-aminopropyltris(trimethylsiloxy)silane,-   3-aminopropyltriethoxysilane,-   1,3-bis(3-aminopropyl)tetramethyldisiloxane,-   N-(2-aminoethyl)-aminopropylmethyldimethoxysila ne,-   3-(1-aminopropoxy)-3,3-dimethyl-1-propenyltrime thoxysilane and-   3-aminopropyltris(methoxyethoxyethoxy)silane.

The amount of primary amine group supported on silica gel is preferably,not limited to, 0.4 to 1.5 μmole per mg of silica gel, more preferably0.5 to 1.2 μmole per mg of silica gel, considering the amount ofaldehydes adsorbed by the silica gel. If the amount of the primary aminegroup supported by silica gel is less than 0.4 μmole/mg, the amount ofthe adsorbent required is increased, which can make the processuneconomical.

In the process for purifying ultraviolet absorbers of the presentinvention, aldehydes are mainly removed in the adsorbent treatment step.The main causative substances of the odor characteristic to ultravioletabsorbers that contain an ester compound of aromatic fatty acid arealdehydes. And such aldehydes are selectively removed by the process forpurifying ultraviolet absorbers of the present invention, wherebyultraviolet absorbers having a reduced odor and an improved hue can beobtained efficiently.

The amount of the adsorbent used is preferably 0.5 to 10 parts by massper 100 parts by mass of ultraviolet absorber and preferably 1 to 5parts by mass. If the amount of the adsorbent used is in the range of0.5 to 10 parts by mass per 100 parts by mass of the ultravioletabsorber, sufficient decoloring and deodorizing effects can be obtainedwhile maintaining the industrial productivity and economy.

The adsorbent treatment step of treating an ultraviolet absorber with anadsorbent by bringing the two into contact with each other can beembodied by various processes. Examples of the processes which embodythe step include: a process in which an ultraviolet absorber and anadsorbent are mixed by stirring; a process in which an ultravioletabsorber is passed through an adsorbent having been packed into a vesselsuch as a column; and a process in which an ultraviolet absorber ispassed through a moving bed of adsorbent.

In the process for purifying ultraviolet absorbers according to thepresent invention, it is preferable, from the viewpoint of industrialproductivity (production cost), influence on the environment, reductionof the number of steps, and safety during the production, not to use asolvent, as described above.

Processes for mixing an ultraviolet absorber and an adsorbent bystirring without using a solvent include: for example, a process inwhich an adsorbent is directly added to an ultraviolet absorber and themixture is heated with stirring preferably at ordinary temperature to120° C., more preferably at ordinary temperature to 100° C., and mostpreferably ordinary temperature to 80° C. The temperature lower thanordinary temperature causes the viscosity of the ultraviolet absorber tobe increased, which may result in poor workability when, for example,carrying out filtration. On the other hand, the temperature higher than120° C. causes the ultraviolet absorber to deteriorate by heating. Inaddition to the mixing operation with stirring, operations for improvingthe dispersion efficiency, such as vibrating the vessel or usingultrasonic, can also be employed depending on the situation.

In the process for purifying ultraviolet absorbers of the presentinvention, deodorizing treatment may be carried out after the adsorbenttreatment step. Adding a deodorizing treatment step makes it possible toremove odor substances which cannot be removed in the adsorbenttreatment step, thereby producing a much highly purified ultravioletabsorber. Particularly when using, as an adsorbent, amino-modifiedsilica gel, which is obtained by allowing silica gel to react with aprimary amine group-containing silane coupling agent, aldehydes arespecifically adsorbed and removed by the amino-modified silica gel, butother odor substances such as alcohols are not removed, and therefore itis preferable to provide a deodorizing treatment step after theadsorbent treatment step.

The process for carrying out the deodorizing treatment step in theprocess for purifying ultraviolet absorbers of the present invention isnot limited to any specific one, and the deodorizing treatment step canbe carried out by any one of the processes commonly used indeodorization of synthetic esters, fat and oil materials or tocopherol.

Processes for carrying out the deodorizing treatment step include: forexample, a process in which an ultraviolet absorber is heated underreduced pressure while blowing nitrogen gas or water vapor over theultraviolet absorber. The degree of vacuum is preferably 4000 Pa orlower, and more preferably 1000 Pa or lower. If the degree of vacuum ishigher than 4000 Pa, the deodorizing treatment has to be carried out athigher temperatures, and heating at such high temperatures may cause theultraviolet absorber to deteriorate. The heating temperature ispreferably 30 to 250° C. and more preferably 80 to 200° C. If thetemperature is lower than 30° C., the odor cannot be fully removed,whereas if the temperature is higher than 250° C., the ultravioletabsorber may be decomposed. The deodorizing treatment time is preferably30 minutes to 20 hours and more preferably 1 hour to 10 hours. If thetreatment time is longer than 20 hours, the ultraviolet absorber maydeteriorate due to the heat.

As described above, in the process of the present invention, it ispreferable to carry out the deodorizing treatment step after theadsorbent treatment step. If the deodorizing treatment step is carriedout before the adsorbent treatment step, not only another odorsubstances may be generated but also the hue may be worsened by heating,which may make it impossible to fully purify the ultraviolet absorber inthe subsequent adsorbent treatment step.

Further, in the process for purifying ultraviolet absorbers according tothe present invention, it is preferable to provide a step of removingthe adsorbent by filtration. If an ultraviolet absorber undergoesdeodorizing treatment with an adsorbent remaining therein, substanceshaving a distinctive odor may be generated by heating at hightemperatures, and the odor substances are unlikely to be removed even bythe subsequent filtration of the adsorbent.

Processes for removing the adsorbent include: besides filtration,centrifugation and sedimentation.

The ultraviolet absorber according to the present invention is anultraviolet absorber having been purified by the process for purifyingultraviolet absorbers of the present invention. The ultraviolet absorberaccording to the present invention has a reduced odor and an excellenthue, compared with unpurified ultraviolet absorbers. Further, theultraviolet absorber according to the present invention contains areduced amount of skin irritating substances, and thus its safety hasbeen improved.

The ultraviolet absorber according to the present invention can be usedin all the products required to have ultraviolet absorbing effects. Asthe products, there con be mentioned; sunscreen cosmetics, suntancosmetics, hand creams, lipsticks and foundations.

The followings are detailed description about the cosmetics according tothe present invention. The cosmetics according to the present inventioncontain an ultraviolet absorber according to the present invention. Theingredients for the cosmetics other than the ultraviolet absorberaccording to the present invention are those commonly used asingredients for ordinary cosmetics and are not limited to any specificones. As the ingredients contained in the cosmetics according to thepresent invention, there can be mentioned; solid, semisolid or liquidoil materials (e.g. natural animal or vegetable fats and oils,semisynthetic fats and oils, hydrocarbon oils, higher fatty acids,higher alcohols, ester oils, silicone oils and fluorine oils); water;alcohols (e.g. lower alcohols, sugar alcohols, sterols and the like);water-soluble polymers (e.g. polymers derived from vegetables such asgum arabic and gum tragacanth, polymers derived from microorganisms suchas xantan gum, dextran, polymers derived from starches such ascarboxymethyl starch and polymers derived from cellulose such ascarboxymethyl cellulose sodium); surfactants (e.g. various types ofanionic, cationic, nonionic or amphoteric surfactants); oil-solublegelling agents (e.g. metallic soap, dextrin fatty acid ester and sucrosefatty acid ester); powders (e.g. inorganic powders such as titaniumoxide, magnesium carbide, mica or hydroxyapatite, and organic powderssuch as polyamide powder); color pigments; pearl pigments; humectants;antiseptics; pH adjustors; chelating agents; refreshing materials;anti-inflammatory agents; skin care ingredients (e.g. whiteningingredients, cell activating ingredients and blood circulationimprover); and vitamins.

The amount of the ultraviolet absorber contained in the cosmetics of thepresent invention is not limited to any specific one, as long as itallows a desired ultraviolet absorbing effect to be produced. Usually,preferably the amount is 0.5 to 20% by mass per 100% by mass of thecosmetics and more preferably 2 to 10% by mass.

EXAMPLE

The present invention will be described in more detail by way ofexamples, below. Such examples, however, are not to be construed aslimiting in any way the scope of the present invention.

Example 1

Amino-modified silica gel as an adsorbent was obtained by treating “MB5D” (spherical silica gel with a pore diameter of 10 nm and a specificsurface area of 250 m²/g), trade name, manufactured by FUJI SILYSIACHEMICAL LTD. with a silane coupling agent having a primary amine groupto modify the surface of the silica gel. The amount of the primary aminegroup supported by the resultant adsorbent was 0.7 μmole per mg ofsilica gel.

Then, adsorbent treatment was carried out in such a manner as to firstadd 1000 g of 2-ethylhexyl p-methoxycinnamate, a commercially availableultraviolet absorber, to a vessel equipped with a stirrer, then add 10 gof the above described adsorbent, and stir the mixture at 80° C. for 1hour. Then, the adsorbent was filtered to obtain a purified oil thatcontains an ultraviolet absorber from which the adsorbent had beenremoved.

The obtained purified oil was fed into a three-neck flask equipped witha nitrogen gas blowing pipe and a thermometer, and deodorizing treatmentwas carried out by heating the purified oil under reduced pressure, at100 to 140° C. and 200 to 800 Pa, for 3 hours while blowing nitrogen gasinto the flask to obtain a purified ultraviolet absorber. Evaluationswere performed for the obtained ultraviolet absorber shown below. Theresults are shown in Table 1. Evaluations were also made for thecommercially available untreated ultraviolet absorbers in the samemanner as in example 1. The results are shown, as those of comparativeexample 1, in Table 1.

<Evaluations for Ultraviolet Absorbers> Odor Evaluation for UltravioletAbsorbers

Sensory evaluation of odor was performed for the ultraviolet absorbers.The intensity of overall odor and that of irritating odor were evaluatedusing one of 10 ranks: 1, no odor; . . . ; 10, very intense odor andscored.

Hue Evaluation for Ultraviolet Absorbers

Hazen color (APHA) was measured using Lovibond Nessleriser 2150.

Odor Evaluation for Ultraviolet Absorbers After a Time Has Elapsed

100 ml of each ultraviolet absorber was filled into two different 200-mlsample bottles, and one bottle was stored in the dark (at 50° C.) andthe other in the light (at 20° C., 1000 lux) for 3 weeks. The intensityof overall odor and that of irritating odor were evaluated using one of10 ranks: 1, no odor; . . . ; 10, very intense odor and scored.

Example 2

An ultraviolet absorber was obtained in the same manner as in example 1,provided that in the deodorizing treatment, instead of nitrogen gas,water vapor was blown into the flask. Evaluations were performed for theobtained ultraviolet absorber in the same manner as in example 1. Theresults are shown in Table 1.

Example 3

An ultraviolet absorber was obtained in the same manner as in example 1,provided that the amount of the adsorbent used was 100 g. Evaluationswere performed for the obtained ultraviolet absorber in the same manneras in example 1. The results are shown in Table 1.

Example 4

100 g of adsorbent, the same type as used in example 1, was filled intoa glass column 30 mm in diameter and a solution of 1000 g ofcommercially available ultraviolet absorber, the same type as used inexample 1, in 2000 g of n-hexane as a solvent was passed through theadsorbent. Then, the solvent was removed from the discharge solution toobtain a purified oil containing the ultraviolet absorber. The samedeodorizing treatment as in example 1 was performed for the obtainedpurified oil to obtain an ultraviolet absorber. Evaluations wereperformed for the obtained ultraviolet absorber in the same manner as inexample 1. The results are shown in Table 1.

Comparative Example 2

Adsorbent treatment was carried out in such a manner as to first add1000 g of 2-ethylhexyl p-methoxycinnamate, a commercially availableultraviolet absorber, to a vessel equipped with a stirrer, then add 10 gof adsorbent, the same type as used in example 1, and stir the mixtureat 80° C. for 1 hour. Then, the adsorbent was filtered to obtain apurified oil that contains an ultraviolet absorber from which theadsorbent had been removed. The purified oil thus obtained was used asan ultraviolet absorber, and evaluations were performed for the obtainedultraviolet absorber in the same manner as in example 1. The results areshown in Table 1.

Comparative Example 3

1000 g of 2-ethylhexyl p-methoxycinnamate, a commercially availableultraviolet absorber, was fed into a three-neck flask equipped with anitrogen gas blowing pipe and a thermometer, and deodorizing treatmentwas carried out by heating the ultraviolet absorber under reducedpressure, at 100 to 140° C. and 200 to 800 Pa, for 3 hours while blowingnitrogen gas into the flask to obtain a purified ultraviolet absorber.Evaluations were performed for the obtained ultraviolet absorber in thesame manner as in example 1. The results are shown in Table 1.

Comparative Example 4

1000 g of 2-ethylhexyl p-methoxycinnamate, a commercially availableultraviolet absorber, was fed into a three-neck flask equipped with anitrogen gas blowing pipe and a thermometer, and deodorizing treatmentwas carried out by heating the ultraviolet absorber under reducedpressure, at 100 to 140° C. and 200 to 800 Pa, for 3 hours while blowingnitrogen gas into the flask. Then, adsorbent treatment was carried outin such a manner as to first add 1000 g of the ultraviolet absorberhaving undergone deodorizing treatment to a vessel equipped with astirrer, then add 10 g of adsorbent, the same-type as used in example 1,and stir the mixture at 80° C. for 1 hour. Then, the adsorbent wasfiltered to obtain a purified oil that contains an ultraviolet absorberfrom which the adsorbent had been removed. Evaluations were performedfor the obtained purified oil, as an ultraviolet absorber, in the samemanner as in example 1. The results are shown in Table 1.

Comparative Example 5

An ultraviolet absorber was obtained in the same manner as in example 1,provided that activated clay was used as an adsorbent. Evaluations wereperformed for the obtained ultraviolet absorber in the same manner as inexample 1. The results are shown in Table 1.

Comparative Example 6

An ultraviolet absorber was obtained in the same manner as in example 1,provided that silica gel (“MB 5D”, trade name, manufactured by FUJISILYSIA CHEMICAL LTD.) not having undergone amino modification was usedas an adsorbent. Evaluations were performed for the obtained ultravioletabsorber in the same manner as in example 1. The results are shown inTable 1.

Comparative Example 7

An ultraviolet absorber was obtained in the same manner as in example 1,provided that activated alumina/magnesia anhydride was used as anadsorbent. Evaluations were performed for the obtained ultravioletabsorber in the same manner as in example 1. The results are shown inTable 1.

Comparative Example 8

An ultraviolet absorber was obtained in the same manner as in example 1,provided that activated silica/alumina hydrate was used as an adsorbent.Evaluations were performed for the obtained ultraviolet absorber in thesame manner as in example 1. The results are shown in Table 1.

Comparative Example 9

Adsorbent treatment was carried out in such a manner that firstly 1000 gof 2-ethylhexyl p-methoxycinnamate, as a commercially availableultraviolet absorber, was added to a vessel equipped with a stirrer,1000 g of hexane was added as a solvent, then 10 g of activatedalumina/magnesia anhydride was added as an adsorbent, and the mixturewas stirred at 25° C. for 1 hour. Then, the adsorbent was filtered andthe solvent was removed from the filtrate to obtain a purified oil thatcontains the ultraviolet absorber. Then the obtained purified oil wassubjected to deodorizing treatment in the same manner as in example 1 toobtain an ultraviolet absorber. Evaluations were performed for theobtained ultraviolet absorber in the same manner as in example 1. Theresults are shown in Table 1. TABLE 1 Odor evaluation for ultravioletEvaluation for absorber after a ultraviolet time has elapsed absorber Inthe In the Odor Hue dark light Example 1 1 10 2 1 Example 2 1 10 2 1Example 3 1 10 2 1 Example 4 1 10 2 1 Comparative 10 40 5 4 example 1Comparative 6 10 5 4 example 2 Comparative 7 40 4 4 example 3Comparative 4 10 4 3 example 4 Comparative 6 20 3 3 example 5Comparative 5 20 3 2 example 6 Comparative 5 10 3 2 example 7Comparative 5 20 3 2 example 8 Comparative 1 10 2 3 example 9

As is apparent from Table 1, the ultraviolet absorbers of examples 1 to4 were ranked high in both the odor and hue evaluations, and moreover,they underwent only a slight change in odor after a time had elapsed.Thus, it is clear that the ultraviolet absorbers of examples 1 to 4 werevastly superior to the unpurified ones. On the other hand, theultraviolet absorbers of comparative examples 1 to 9 were ranked lowcompared with those of examples 1 to 4, though their odor and hue wereimproved compared with the unpurified ultraviolet absorbers.

ADVANTAGE OF THE INVENTION

According to the present invention, a process for purifying ultravioletabsorbers can be provided which can improve the odor and hue ofultraviolet absorbers and excels in industrial productivity. The use ofthe purifying process makes it possible to provide ultraviolet absorbershaving a reduced odor and an improved hue and excelling in safety. Theuse of the ultraviolet absorbers, in turn, makes it possible to providecosmetics having a reduced characteristic odor and less skin irritationand excelling in safety.

1. A process for purifying an ultraviolet absorber, comprising anadsorbent treatment step of bringing the ultraviolet absorber intocontact with the adsorbent.
 2. The process for purifying an ultravioletabsorber according to claim 1, wherein the adsorbent is amino-modifiedsilica gel obtained by allowing silica gel to react with a silanecoupling agent having a primary amine group to modify the surface of thesilica gel.
 3. The process for purifying an ultraviolet absorberaccording to claim 2, wherein the amount of the primary amine groupsupported on the adsorbent is 0.4 to 1.5 μmole per mg of silica gel. 4.The process for purifying an ultraviolet absorber according to claim 1,wherein the ultraviolet absorber comprises at least one kind of estercompound that is composed of an aromatic fatty acid and a monohydric- orpolyhydric-alcohol.
 5. The process for purifying an ultraviolet absorberaccording to claim 1, wherein the ultraviolet absorber comprises atleast one kind of ester compound that is composed of methoxycinnamicacid and a monohydric- or polyhydric-alcohol.
 6. The process forpurifying an ultraviolet absorber according to claim 1, furthercomprising a deodorizing treatment step after the adsorbent treatmentstep.
 7. An ultraviolet absorber, purified by the process for purifyingan ultraviolet absorber according to claim
 1. 8. A cosmetic containingan ultraviolet absorber according to claim
 7. 9. The process forpurifying an ultraviolet absorber according to claim 2, wherein theultraviolet absorber comprises at least one kind of ester compound thatis composed of an aromatic fatty acid and a monohydric- orpolyhydric-alcohol.
 10. The process for purifying an ultravioletabsorber according to claim 3, wherein the ultraviolet absorbercomprises at least one kind of ester compound that is composed of anaromatic fatty acid and a monohydric- or polyhydric-alcohol.
 11. Theprocess for purifying an ultraviolet absorber according to claim 2,wherein the ultraviolet absorber comprises at least one kind of estercompound that is composed of methoxycinnamic acid and a monohydric- orpolyhydric-alcohol.
 12. The process for purifying an ultravioletabsorber according to claim 3, wherein the ultraviolet absorbercomprises at least one kind of ester compound that is composed ofmethoxycinnamic acid and a monohydric- or polyhydric-alcohol.
 13. Theprocess for purifying an ultraviolet absorber according to claim 2,further comprising a deodorizing treatment step after the adsorbenttreatment step.
 14. The process for purifying an ultraviolet absorberaccording to claim 3, further comprising a deodorizing treatment stepafter the adsorbent treatment step.
 15. The process for purifying anultraviolet absorber according to claim 4, further comprising adeodorizing treatment step after the adsorbent treatment step.
 16. Theprocess for purifying an ultraviolet absorber according to claim 5,further comprising a deodorizing treatment step after the adsorbenttreatment step.
 17. An ultraviolet absorber, purified by the process forpurifying an ultraviolet absorber according to claim
 2. 18. A cosmeticcontaining an ultraviolet absorber according to claim
 17. 19. Anultraviolet absorber, purified by the process for purifying anultraviolet absorber according to claim
 3. 20. A cosmetic containing anultraviolet absorber according to claim 19.